USAP-DC

{"dp_type": "Project", "free_text": "Pine Island Glacier"}

[{"awards": "1643285 Joughin, Ian; 1643174 Padman, Laurence", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}, {"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}, {"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties.\r\nThis project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations.\r\nIntellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project\u2019s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.\r\nBroader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences.\r\n\r\nThis proposal does not require fieldwork in the Antarctic.\r\n", "east": -86.0, "geometry": "POINT(-95 -77)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; ICE SHEETS; AMD; USAP-DC; MODELS; AMD/US; Pine Island Glacier", "locations": "Pine Island Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "Uni. Washington ResearchWorks Archive", "repositories": "GitHub; Uni. Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "1643652 Hofmann, Eileen; 1643618 Arrigo, Kevin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic biological model output; Antarctic dFe model dyes", "datasets": [{"dataset_uid": "200210", "doi": "10.26008/1912/bco-dmo.782848.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic dFe model dyes", "url": "https://www.bco-dmo.org/dataset/782848"}, {"dataset_uid": "200211", "doi": "10.26008/1912/bco-dmo.858663.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic biological model output", "url": "https://www.bco-dmo.org/dataset/858663"}], "date_created": "Thu, 29 Apr 2021 00:00:00 GMT", "description": "Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail.\r\nThis project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings.\r\nThe project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts.\r\n\r\nPolynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers.\r\nIn this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for \u003e50% of the total Antarctic polynya production.\r\nThe research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent?\r\nThe Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "trace metal; AMD; Polynas; PELAGIC; POLYNYAS; PHYTOPLANKTON; MODELS; USAP-DC; MICROALGAE; USA/NSF; TRACE ELEMENTS; ICE SHEETS; Antarctica; AMD/US", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula", "uid": "p0010175", "west": -180.0}, {"awards": "2317097 Venturelli, Ryan; 1738989 Venturelli, Ryan", "bounds_geometry": "POLYGON((-114 -74,-112.2 -74,-110.4 -74,-108.6 -74,-106.8 -74,-105 -74,-103.2 -74,-101.4 -74,-99.6 -74,-97.8 -74,-96 -74,-96 -74.2,-96 -74.4,-96 -74.6,-96 -74.8,-96 -75,-96 -75.2,-96 -75.4,-96 -75.6,-96 -75.8,-96 -76,-97.8 -76,-99.6 -76,-101.4 -76,-103.2 -76,-105 -76,-106.8 -76,-108.6 -76,-110.4 -76,-112.2 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica; Cosmogenic-Nuclide data at ICE-D; In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers; NBP1902 Expedition data; Pine Island Bay Relative Sea-Level Data", "datasets": [{"dataset_uid": "200296", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601677", "doi": "10.15784/601677", "keywords": "Antarctica; Cryosphere; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601677"}, {"dataset_uid": "601554", "doi": "10.15784/601554", "keywords": "Antarctica; Cryosphere; Pine Island Bay; Radiocarbon; Raised Beaches", "people": "Braddock, Scott; Hall, Brenda", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Pine Island Bay Relative Sea-Level Data", "url": "https://www.usap-dc.org/view/dataset/601554"}, {"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "601705", "doi": "10.15784/601705", "keywords": "Antarctica; cosmogenic nuclides; Cryosphere; Mount Murphy; Subglacial Bedrock", "people": "Venturelli, Ryan; Balco, Gregory; Goehring, Brent", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "url": "https://www.usap-dc.org/view/dataset/601705"}], "date_created": "Tue, 16 Mar 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. \r\n\r\nThe team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration.", "east": -96.0, "geometry": "POINT(-105 -75)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; GLACIERS/ICE SHEETS; GLACIAL LANDFORMS; LABORATORY; USAP-DC; GLACIATION; Amundsen Sea; AMD/US; USA/NSF", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Goehring, Brent; Hall, Brenda; Campbell, Seth; Venturelli, Ryan A; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "uid": "p0010165", "west": -114.0}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": "POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65))", "dataset_titles": "Expedition Data; R/V Nathaniel B. Palmer NBP0008 - Expedition Data; \r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "200022", "doi": "10.15784/601161 ", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "\r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "200023", "doi": "10.7284/905461", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "R/V Nathaniel B. Palmer NBP0008 - Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Mon, 11 Mar 2019 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999.", "east": 150.0, "geometry": "POINT(145 -66.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC; Southern Ocean; WATER MASSES; Antarctica", "locations": "Southern Ocean; Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Visbeck, Martin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.0, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0010019", "west": 140.0}, {"awards": "0632282 Jacobs, Stanley", "bounds_geometry": "POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2))", "dataset_titles": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901; NBP07-09 cruise data; NBP07-09 processed CTD data; NBP09-01 cruise data; NBP09-01 processed CTD data; Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "datasets": [{"dataset_uid": "601349", "doi": null, "keywords": "Amundsen Sea; Antarctica; Cryosphere; Current Measurements; LADCP; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; R/V Nathaniel B. Palmer; Southern Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601349"}, {"dataset_uid": "601350", "doi": null, "keywords": "Amundsen Sea; Antarctic; Antarctica; Cryosphere; CTD; CTD Data; Current Measurements; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; Pine Island Glacier; R/V Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Huber, Bruce; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601350"}, {"dataset_uid": "000130", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP09-01 processed CTD data", "url": "http://accession.nodc.noaa.gov/0071179"}, {"dataset_uid": "000129", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP09-01 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0901"}, {"dataset_uid": "000128", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP07-09 processed CTD data", "url": "http://accession.nodc.noaa.gov/0120761"}, {"dataset_uid": "000127", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP07-09 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0709"}], "date_created": "Fri, 25 Sep 2015 00:00:00 GMT", "description": "The Office of Polar Programs, Antarctic Science Division, Ocean \u0026 Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. \u003cbr/\u003eThe region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. \u003cbr/\u003eBroader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.", "east": -78.0, "geometry": "POINT(-103.8 -64.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "Not provided; R/V NBP", "locations": null, "north": -54.2, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP; Not provided", "repo": "USAP-DC", "repositories": "NCEI; R2R; USAP-DC", "science_programs": null, "south": -75.1, "title": "IPY/ASEP - Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise.", "uid": "p0000332", "west": -129.6}, {"awards": "0732804 McPhee, Miles; 0732906 Nowicki, Sophie; 0732869 Holland, David; 0732730 Truffer, Martin", "bounds_geometry": "POINT(-100.728 -75.0427)", "dataset_titles": "Automatic Weather Station Pine Island Glacier; Borehole Temperatures at Pine Island Glacier, Antarctica; Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "datasets": [{"dataset_uid": "601216", "doi": "10.15784/601216", "keywords": "Antarctica; Atmosphere; Atmospheric; Automated Weather Station (AWS); Cryosphere; Fluxes; Glaciers/Ice Sheet; Glaciology; Meteorology; Pine Island Glacier; Weather Station Data", "people": "Mojica Moncada, Jhon F.; Holland, David", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}, {"dataset_uid": "600072", "doi": "10.15784/600072", "keywords": "Antarctica; Atmosphere; Cryosphere; McMurdo; Meteorology; Oceans; Ross Island; Southern Ocean", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "url": "https://www.usap-dc.org/view/dataset/600072"}, {"dataset_uid": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Truffer, Martin; Stanton, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}], "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 \u003cbr/\u003eTitle: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica\u003cbr/\u003e\u003cbr/\u003eThe Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the \"Multidisciplinary Study of the Amundsen Sea Embayment\" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded \"Polar Palooza\" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.", "east": -100.728, "geometry": "POINT(-100.728 -75.0427)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": true, "keywords": "West Antarctica; Melt; Seismic; AGDC; LABORATORY; stability; AGDC-project; Ocean-Ice Interaction; Remote Sensing; COMPUTERS; FIELD SURVEYS; LANDSAT-8; Boreholes; Ice Motion; FIELD INVESTIGATION; ocean profiling; AUVS; sea-level rise; Not provided; Deformation; SATELLITES; Amundsen Sea Sector; GROUND-BASED OBSERVATIONS; Ice Temperature; International Polar Year", "locations": "West Antarctica", "north": -75.0427, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G.", "platforms": "WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-8; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e COMPUTERS; Not provided; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0427, "title": "Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica", "uid": "p0000043", "west": -100.728}, {"awards": "0934534 Sergienko, Olga", "bounds_geometry": "POLYGON((-106 -70,-105.4 -70,-104.8 -70,-104.2 -70,-103.6 -70,-103 -70,-102.4 -70,-101.8 -70,-101.2 -70,-100.6 -70,-100 -70,-100 -70.6,-100 -71.2,-100 -71.8,-100 -72.4,-100 -73,-100 -73.6,-100 -74.2,-100 -74.8,-100 -75.4,-100 -76,-100.6 -76,-101.2 -76,-101.8 -76,-102.4 -76,-103 -76,-103.6 -76,-104.2 -76,-104.8 -76,-105.4 -76,-106 -76,-106 -75.4,-106 -74.8,-106 -74.2,-106 -73.6,-106 -73,-106 -72.4,-106 -71.8,-106 -71.2,-106 -70.6,-106 -70))", "dataset_titles": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "datasets": [{"dataset_uid": "609626", "doi": "10.7265/N5XS5SBW", "keywords": "Antarctica; Arctic; Bindschadler Ice Stream; Cryosphere; Glaciers/Ice Sheet; Glaciology; Greenland; Lambert Ice Stream; MacAyeal Ice Stream; Pine Island Glacier; Thwaites Glacier", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "url": "https://www.usap-dc.org/view/dataset/609626"}], "date_created": "Thu, 06 Feb 2014 00:00:00 GMT", "description": "Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.", "east": -100.0, "geometry": "POINT(-103 -73)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "Not provided; AGDC-project; AGDC; inverse model; GROUND-BASED OBSERVATIONS; Basal Shear Stress", "locations": null, "north": -70.0, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Sergienko, Olga", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "COLLABORATIVE RESEARCH: Enabling ice sheet sensitivity and stability analysis with a large-scale higher-order ice sheet model\u0027s adjoint to support sea level change assessment", "uid": "p0000048", "west": -106.0}, {"awards": "0632198 Anandakrishnan, Sridhar", "bounds_geometry": "POINT(110 -74)", "dataset_titles": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Parizek, Byron R.; Blankenship, Donald D.; Dupont, Todd K.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}], "date_created": "Wed, 29 Aug 2012 00:00:00 GMT", "description": "This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this \"pulse of activity\" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.", "east": -110.0, "geometry": "POINT(-110 -74)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": false, "keywords": "thickness; ice-sheet modeling; tidal forcing; subglacial; Pine Island Glacier; Ice Dynamics; FIELD INVESTIGATION; Not provided; Thwaites; LABORATORY; Amundsen Sea Embayment; bed reflection; FIELD SURVEYS; position", "locations": "Amundsen Sea Embayment; Pine Island Glacier", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.", "uid": "p0000699", "west": -110.0}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0001; Expedition data of NBP0008; Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "002598", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0001", "url": "https://www.rvdata.us/search/cruise/NBP0001"}, {"dataset_uid": "002599", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0008", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "601161", "doi": "10.15784/601161 ", "keywords": "Antarctica; Cryosphere; CTD; CTD Data; Mertz Polynya; NBP0008; Oceans; Oxygen; Physical Oceanography; R/V Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Mortlock, R. A.; Smethie, William M; Mele, Phil; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0000815", "west": null}, {"awards": "0440775 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0702; NBP0702 surface sediment sample information and images", "datasets": [{"dataset_uid": "601473", "doi": "10.15784/601473", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Marine Geoscience; Marine Sediments; NBP0702; Photographs; R/V Nathaniel B. Palmer; Seafloor Sampling; Sediment Description; Smith-McIntyre Grab", "people": "Jacobs, Stanley; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP0702 surface sediment sample information and images", "url": "https://www.usap-dc.org/view/dataset/601473"}, {"dataset_uid": "002645", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0702", "url": "https://www.rvdata.us/search/cruise/NBP0702"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "AMD; R/V NBP; NSF/USA; Amundsen Sea; AMD/US; USAP-DC", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "The Amundsen Continental Shelf and the Antarctic Ice Sheet", "uid": "p0000836", "west": null}, {"awards": "0230197 Holt, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Amundsen Sea Sector Data Set; Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "datasets": [{"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "AntArchitecture; Antarctica; Cryosphere; Ice Penetrating Radar; Isochron; layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea Embayment; Antarctica; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Vaughan, David G.; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Corr, Hugh F. J.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609292"}, {"dataset_uid": "609312", "doi": "10.7265/N5J9649Q", "keywords": "Amundsen Sea Embayment; Antarctica; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology", "people": "Fastook, James L.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Sector Data Set", "url": "https://www.usap-dc.org/view/dataset/609312"}], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical\u003cbr/\u003edata will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.\u003cbr/\u003eThe West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea\u003cbr/\u003elevel rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical\u003cbr/\u003ecenters. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.\u003cbr/\u003eThe results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.\u003cbr/\u003eThrough its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": true, "keywords": "Thwaites Glacier; Airborne geophysical survey of the Amundsen Sea Embayment; Amundsen Sea Embayment; Ice Velocity; Melt; Ablation; Pine Island Glacier; Elevation; Antarctica (AGASEA); Ice Sheet Elevation; West Antarctic Ice Sheet; Ice Temperature; Amundsen Basin; Subglacial Topography; AGDC; Ice Melt; West Antarctica; Velocity Measurements; Snow Accumulation; Antarctica; Bedrock Elevation; Modeling", "locations": "Amundsen Sea Embayment; Antarctica; West Antarctica; Amundsen Basin; Pine Island Glacier; Thwaites Glacier; West Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "uid": "p0000243", "west": -180.0}, {"awards": "0126187 Alley, Richard", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 Apr 2006 00:00:00 GMT", "description": "0126187\u003cbr/\u003eAlley\u003cbr/\u003e\u003cbr/\u003eThis award provides support for a 2 year modeling effort to study the dynamics of Pine Island Glacier (PIG). The discharge from the PIG constitutes the largest mass loss from any single West Antarctic ice stream. Satellite observations indicate that this outlet glacier is experiencing ongoing thinning and acceleration. The emphasis of this work will be on understanding the cause and the near-term projection of the observed thinning of PIG. Model experiments will address the hypothesis that the observed changes were caused by the loss of a buttressing ice shelf, and that the changes will continue in the form of an upglacier propagating wave of thinning and acceleration. To perform this work a numerical model of the coupled mass, energy, and momentum balance of Pine Island Glacier basin will be developed. The model will comprise four modular components, which will be coupled and then benchmarked against the European Ice Sheet Modeling Inititative (EISMINT) model intercomparison. The model will then be applied to the thinning of Pine Island Glacier using likely ice-shelf histories and possible basal boundary conditions to learn which may be accurate and to assess possible future behavior. The primary expected result will be an improved understanding of the importance of ice-shelf buttressing and the potential for inland thinning due to the reduction of ice-shelf drag.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Dupont, Todd K.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "The Thinning of Pine Island Glacier: Model Development and Study of the Importance of Ice-Shelf Drag on Inland Ice", "uid": "p0000715", "west": null}]

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